Memory loss is one of the most pervasive mental disorders associated with Senile Dementia of the Alzheimer's Type (SDAT). Failure of prospective memory (remembering to perform a future action) is a major concern to both individuals with SDAT and to their caregivers. Spaced-retrieval training, previously successful in aiding memory in this population, will be used to enhance performance in prospective memory tasks. This training, which involves practicing recall of newly-learned information after increasingly longer intervals, is a form of shaping, and produces closer and closer approximations to a desired goal -- long term retention of information. The intent of the proposed intervention is to use spaced-retrieval training to facilitate the efficient use of a versatile external memory aid - a calendar. The aim is to use the training to allow participants to learn and retain a specific internally-stored strategy -- look at the calendar when you want to remember what to do. To use the calendar as an external memory aid, participants must: a) learn and retain an internal memory (the trained strategy); b) translate the strategy into action (go to the calendar); and c) execute activities written on the calendar. The ability to accomplish each of these steps, singly and in concert, will be assessed in 192 individuals with SDAT. Control procedures using yoked pairs of participants will allow us to determine if the active recall required by the spaced-retrieval technique is significantly more effective than passive presentation at the same expanding interval schedules at enhancing retention for these individuals. The impact of spaced-retrieval training on general memory ability will also be assessed. In summary, the study will address the extent to which a strategy can be trained with spaced-retrieval techniques, and whether the combination of training a strategy and providing an external memory aid can be used to allow individuals with SDAT to effectively execute prospective memory tasks. If successful, this intervention could greatly enhance both independence and self-esteem.